/*
 * DHD debug ring API and structures
 *
 * <<Broadcom-WL-IPTag/Open:>>
 *
 * Copyright (C) 1999-2019, Broadcom.
 *
 *      Unless you and Broadcom execute a separate written software license
 * agreement governing use of this software, this software is licensed to you
 * under the terms of the GNU General Public License version 2 (the "GPL"),
 * available at http://www.broadcom.com/licenses/GPLv2.php, with the
 * following added to such license:
 *
 *      As a special exception, the copyright holders of this software give you
 * permission to link this software with independent modules, and to copy and
 * distribute the resulting executable under terms of your choice, provided that
 * you also meet, for each linked independent module, the terms and conditions
 * of the license of that module.  An independent module is a module which is
 * not derived from this software.  The special exception does not apply to any
 * modifications of the software.
 *
 *      Notwithstanding the above, under no circumstances may you combine this
 * software in any way with any other Broadcom software provided under a license
 * other than the GPL, without Broadcom's express prior written consent.
 *
 * $Id: dhd_dbg_ring.c 792099 2018-12-03 15:45:56Z $
 */
#include <typedefs.h>
#include <osl.h>
#include <bcmutils.h>
#include <bcmendian.h>
#include <dngl_stats.h>
#include <dhd.h>
#include <dhd_dbg.h>
#include <dhd_dbg_ring.h>

int dhd_dbg_ring_init(dhd_pub_t *dhdp, dhd_dbg_ring_t *ring, uint16 id,
                      uint8 *name, uint32 ring_sz, void *allocd_buf,
                      bool pull_inactive)
{
    void *buf;
    unsigned long flags = 0;

    if (allocd_buf == NULL) {
        return BCME_NOMEM;
    } else {
        buf = allocd_buf;
    }

    ring->lock = DHD_DBG_RING_LOCK_INIT(dhdp->osh);
    if (!ring->lock) {
        return BCME_NOMEM;
    }

    DHD_DBG_RING_LOCK(ring->lock, flags);
    ring->id = id;
    strncpy(ring->name, name, DBGRING_NAME_MAX);
    ring->name[DBGRING_NAME_MAX - 1] = 0;
    ring->ring_size = ring_sz;
    ring->wp = ring->rp = 0;
    ring->ring_buf = buf;
    ring->threshold = DBGRING_FLUSH_THRESHOLD(ring);
    ring->state = RING_SUSPEND;
    ring->rem_len = 0;
    ring->sched_pull = TRUE;
    ring->pull_inactive = pull_inactive;
    DHD_DBG_RING_UNLOCK(ring->lock, flags);

    return BCME_OK;
}

void dhd_dbg_ring_deinit(dhd_pub_t *dhdp, dhd_dbg_ring_t *ring)
{
    unsigned long flags = 0;
    DHD_DBG_RING_LOCK(ring->lock, flags);
    ring->id = 0;
    ring->name[0] = 0;
    ring->wp = ring->rp = 0;
    memset(&ring->stat, 0, sizeof(ring->stat));
    ring->threshold = 0;
    ring->state = RING_STOP;
    DHD_DBG_RING_UNLOCK(ring->lock, flags);

    DHD_DBG_RING_LOCK_DEINIT(dhdp->osh, ring->lock);
}

void dhd_dbg_ring_sched_pull(dhd_dbg_ring_t *ring, uint32 pending_len,
                             os_pullreq_t pull_fn, void *os_pvt, const int id)
{
    unsigned long flags = 0;
    DHD_DBG_RING_LOCK(ring->lock, flags);
    /* if the current pending size is bigger than threshold and
     * threshold is set
     */
    if (ring->threshold > 0 && (pending_len >= ring->threshold) &&
        ring->sched_pull) {
        /*
         * Update the state and release the lock before calling
         * the pull_fn. Do not transfer control to other layers
         * with locks held. If the call back again calls into
         * the same layer fro this context, can lead to deadlock.
         */
        ring->sched_pull = FALSE;
        DHD_DBG_RING_UNLOCK(ring->lock, flags);
        pull_fn(os_pvt, id);
    } else {
        DHD_DBG_RING_UNLOCK(ring->lock, flags);
    }
}

uint32 dhd_dbg_ring_get_pending_len(dhd_dbg_ring_t *ring)
{
    uint32 pending_len = 0;
    unsigned long flags = 0;
    DHD_DBG_RING_LOCK(ring->lock, flags);
    if (ring->stat.written_bytes > ring->stat.read_bytes) {
        pending_len = ring->stat.written_bytes - ring->stat.read_bytes;
    } else if (ring->stat.written_bytes < ring->stat.read_bytes) {
        pending_len =
            PENDING_LEN_MAX - ring->stat.read_bytes + ring->stat.written_bytes;
    } else {
        pending_len = 0;
    }
    DHD_DBG_RING_UNLOCK(ring->lock, flags);

    return pending_len;
}

int dhd_dbg_ring_push(dhd_dbg_ring_t *ring, dhd_dbg_ring_entry_t *hdr,
                      void *data)
{
    unsigned long flags;
    uint32 w_len;
    uint32 avail_size;
    dhd_dbg_ring_entry_t *w_entry, *r_entry;

    if (!ring || !hdr || !data) {
        return BCME_BADARG;
    }

    DHD_DBG_RING_LOCK(ring->lock, flags);

    if (ring->state != RING_ACTIVE) {
        DHD_DBG_RING_UNLOCK(ring->lock, flags);
        return BCME_OK;
    }

    w_len = ENTRY_LENGTH(hdr);

    DHD_DBGIF(
        ("%s: RING%d[%s] hdr->len=%u, w_len=%u, wp=%d, rp=%d, ring_start=0x%p;"
         " ring_size=%u\n",
         __FUNCTION__, ring->id, ring->name, hdr->len, w_len, ring->wp,
         ring->rp, ring->ring_buf, ring->ring_size));

    if (w_len > ring->ring_size) {
        DHD_DBG_RING_UNLOCK(ring->lock, flags);
        DHD_ERROR(("%s: RING%d[%s] w_len=%u, ring_size=%u,"
                   " write size exceeds ring size !\n",
                   __FUNCTION__, ring->id, ring->name, w_len, ring->ring_size));
        return BCME_BUFTOOLONG;
    }
    /* Claim the space */
    do {
        avail_size =
            DBG_RING_CHECK_WRITE_SPACE(ring->rp, ring->wp, ring->ring_size);
        if (avail_size <= w_len) {
            /* Prepare the space */
            if (ring->rp <= ring->wp) {
                ring->tail_padded = TRUE;
                ring->rem_len = ring->ring_size - ring->wp;
                DHD_DBGIF(("%s: RING%d[%s] Insuffient tail space,"
                           " rp=%d, wp=%d, rem_len=%d, ring_size=%d,"
                           " avail_size=%d, w_len=%d\n",
                           __FUNCTION__, ring->id, ring->name, ring->rp,
                           ring->wp, ring->rem_len, ring->ring_size, avail_size,
                           w_len));

                /* 0 pad insufficient tail space */
                memset((uint8 *)ring->ring_buf + ring->wp, 0, ring->rem_len);
                /* If read pointer is still at the beginning, make some room */
                if (ring->rp == 0) {
                    r_entry = (dhd_dbg_ring_entry_t *)((uint8 *)ring->ring_buf +
                                                       ring->rp);
                    ring->rp += ENTRY_LENGTH(r_entry);
                    ring->stat.read_bytes += ENTRY_LENGTH(r_entry);
                    DHD_DBGIF(("%s: rp at 0, move by one entry length"
                               " (%u bytes)\n",
                               __FUNCTION__, (uint32)ENTRY_LENGTH(r_entry)));
                }
                if (ring->rp == ring->wp) {
                    ring->rp = 0;
                }
                ring->wp = 0;
                DHD_DBGIF(("%s: new rp=%u, wp=%u\n", __FUNCTION__, ring->rp,
                           ring->wp));
            } else {
                /* Not enough space for new entry, free some up */
                r_entry = (dhd_dbg_ring_entry_t *)((uint8 *)ring->ring_buf +
                                                   ring->rp);
                /* check bounds before incrementing read ptr */
                if (ring->rp + ENTRY_LENGTH(r_entry) >= ring->ring_size) {
                    DHD_ERROR(("%s: RING%d[%s] rp points out of boundary, "
                               "ring->wp=%u, ring->rp=%u, ring->ring_size=%d\n",
                               __FUNCTION__, ring->id, ring->name, ring->wp,
                               ring->rp, ring->ring_size));
                    ASSERT(0);
                    DHD_DBG_RING_UNLOCK(ring->lock, flags);
                    return BCME_BUFTOOSHORT;
                }
                ring->rp += ENTRY_LENGTH(r_entry);
                /* skip padding if there is one */
                if (ring->tail_padded &&
                    ((ring->rp + ring->rem_len) == ring->ring_size)) {
                    DHD_DBGIF(("%s: RING%d[%s] Found padding,"
                               " avail_size=%d, w_len=%d, set rp=0\n",
                               __FUNCTION__, ring->id, ring->name, avail_size,
                               w_len));
                    ring->rp = 0;
                    ring->tail_padded = FALSE;
                    ring->rem_len = 0;
                }
                ring->stat.read_bytes += ENTRY_LENGTH(r_entry);
                DHD_DBGIF(("%s: RING%d[%s] read_bytes=%d, wp=%d, rp=%d\n",
                           __FUNCTION__, ring->id, ring->name,
                           ring->stat.read_bytes, ring->wp, ring->rp));
            }
        } else {
            break;
        }
    } while (TRUE);

    /* check before writing to the ring */
    if (ring->wp + w_len >= ring->ring_size) {
        DHD_ERROR(("%s: RING%d[%s] wp pointed out of ring boundary, "
                   "wp=%d, ring_size=%d, w_len=%u\n",
                   __FUNCTION__, ring->id, ring->name, ring->wp,
                   ring->ring_size, w_len));
        ASSERT(0);
        DHD_DBG_RING_UNLOCK(ring->lock, flags);
        return BCME_BUFTOOLONG;
    }

    w_entry = (dhd_dbg_ring_entry_t *)((uint8 *)ring->ring_buf + ring->wp);
    /* header */
    memcpy(w_entry, hdr, DBG_RING_ENTRY_SIZE);
    w_entry->len = hdr->len;
    /* payload */
    memcpy((char *)w_entry + DBG_RING_ENTRY_SIZE, data, w_entry->len);
    /* update write pointer */
    ring->wp += w_len;

    /* update statistics */
    ring->stat.written_records++;
    ring->stat.written_bytes += w_len;
    DHD_DBGIF(
        ("%s : RING%d[%s] written_records %d, written_bytes %d, read_bytes=%d,"
         " ring->threshold=%d, wp=%d, rp=%d\n",
         __FUNCTION__, ring->id, ring->name, ring->stat.written_records,
         ring->stat.written_bytes, ring->stat.read_bytes, ring->threshold,
         ring->wp, ring->rp));

    DHD_DBG_RING_UNLOCK(ring->lock, flags);
    return BCME_OK;
}

/*
 * This function folds ring->lock, so callers of this function
 * should not hold ring->lock.
 */
int dhd_dbg_ring_pull_single(dhd_dbg_ring_t *ring, void *data, uint32 buf_len,
                             bool strip_header)
{
    dhd_dbg_ring_entry_t *r_entry = NULL;
    uint32 rlen = 0;
    char *buf = NULL;
    unsigned long flags;

    if (!ring || !data || buf_len <= 0) {
        return 0;
    }

    DHD_DBG_RING_LOCK(ring->lock, flags);

    /* pull from ring is allowed for inactive (suspended) ring
     * in case of ecounters only, this is because, for ecounters
     * when a trap occurs the ring is suspended and data is then
     * pulled to dump it to a file. For other rings if ring is
     * not in active state return without processing (as before)
     */
    if (!ring->pull_inactive && (ring->state != RING_ACTIVE)) {
        goto exit;
    }

    if (ring->rp == ring->wp) {
        goto exit;
    }

    DHD_DBGIF(("%s: RING%d[%s] buf_len=%u, wp=%d, rp=%d, ring_start=0x%p; "
               "ring_size=%u\n",
               __FUNCTION__, ring->id, ring->name, buf_len, ring->wp, ring->rp,
               ring->ring_buf, ring->ring_size));

    r_entry = (dhd_dbg_ring_entry_t *)((uint8 *)ring->ring_buf + ring->rp);

    /* Boundary Check */
    rlen = ENTRY_LENGTH(r_entry);
    if ((ring->rp + rlen) > ring->ring_size) {
        DHD_ERROR(("%s: entry len %d is out of boundary of ring size %d,"
                   " current ring %d[%s] - rp=%d\n",
                   __FUNCTION__, rlen, ring->ring_size, ring->id, ring->name,
                   ring->rp));
        rlen = 0;
        goto exit;
    }

    if (strip_header) {
        rlen = r_entry->len;
        buf = (char *)r_entry + DBG_RING_ENTRY_SIZE;
    } else {
        rlen = ENTRY_LENGTH(r_entry);
        buf = (char *)r_entry;
    }
    if (rlen > buf_len) {
        DHD_ERROR(("%s: buf len %d is too small for entry len %d\n",
                   __FUNCTION__, buf_len, rlen));
        DHD_ERROR(("%s: ring %d[%s] - ring size=%d, wp=%d, rp=%d\n",
                   __FUNCTION__, ring->id, ring->name, ring->ring_size,
                   ring->wp, ring->rp));
        ASSERT(0);
        rlen = 0;
        goto exit;
    }

    memcpy(data, buf, rlen);
    /* update ring context */
    ring->rp += ENTRY_LENGTH(r_entry);
    /* don't pass wp but skip padding if there is one */
    if (ring->rp != ring->wp && ring->tail_padded &&
        ((ring->rp + ring->rem_len) >= ring->ring_size)) {
        DHD_DBGIF(("%s: RING%d[%s] Found padding, rp=%d, wp=%d\n", __FUNCTION__,
                   ring->id, ring->name, ring->rp, ring->wp));
        ring->rp = 0;
        ring->tail_padded = FALSE;
        ring->rem_len = 0;
    }
    if (ring->rp >= ring->ring_size) {
        DHD_ERROR(("%s: RING%d[%s] rp pointed out of ring boundary,"
                   " rp=%d, ring_size=%d\n",
                   __FUNCTION__, ring->id, ring->name, ring->rp,
                   ring->ring_size));
        ASSERT(0);
        rlen = 0;
        goto exit;
    }
    ring->stat.read_bytes += ENTRY_LENGTH(r_entry);
    DHD_DBGIF(("%s RING%d[%s]read_bytes %d, wp=%d, rp=%d\n", __FUNCTION__,
               ring->id, ring->name, ring->stat.read_bytes, ring->wp,
               ring->rp));

exit:
    DHD_DBG_RING_UNLOCK(ring->lock, flags);

    return rlen;
}

int dhd_dbg_ring_pull(dhd_dbg_ring_t *ring, void *data, uint32 buf_len,
                      bool strip_hdr)
{
    int32 r_len, total_r_len = 0;
    unsigned long flags;

    if (!ring || !data) {
        return 0;
    }

    DHD_DBG_RING_LOCK(ring->lock, flags);
    if (!ring->pull_inactive && (ring->state != RING_ACTIVE)) {
        DHD_DBG_RING_UNLOCK(ring->lock, flags);
        return 0;
    }
    DHD_DBG_RING_UNLOCK(ring->lock, flags);

    while (buf_len > 0) {
        r_len = dhd_dbg_ring_pull_single(ring, data, buf_len, strip_hdr);
        if (r_len == 0) {
            break;
        }
        data = (uint8 *)data + r_len;
        buf_len -= r_len;
        total_r_len += r_len;
    }

    return total_r_len;
}

int dhd_dbg_ring_config(dhd_dbg_ring_t *ring, int log_level, uint32 threshold)
{
    unsigned long flags = 0;
    if (!ring) {
        return BCME_BADADDR;
    }

    if (ring->state == RING_STOP) {
        return BCME_UNSUPPORTED;
    }

    DHD_DBG_RING_LOCK(ring->lock, flags);

    if (log_level == 0) {
        ring->state = RING_SUSPEND;
    } else {
        ring->state = RING_ACTIVE;
    }

    ring->log_level = log_level;
    ring->threshold = MIN(threshold, DBGRING_FLUSH_THRESHOLD(ring));

    DHD_DBG_RING_UNLOCK(ring->lock, flags);

    return BCME_OK;
}

void dhd_dbg_ring_start(dhd_dbg_ring_t *ring)
{
    if (!ring) {
        return;
    }

    /* Initialize the information for the ring */
    ring->state = RING_SUSPEND;
    ring->log_level = 0;
    ring->rp = ring->wp = 0;
    ring->threshold = 0;
    memset(&ring->stat, 0, sizeof(struct ring_statistics));
    memset(ring->ring_buf, 0, ring->ring_size);
}
